 The field surveyor who traveled to Sycamore in 1973 found a large number of late 19th and 20th century examples of architecture that he recommended the establishment of a historic district.The mayor of Sycamore then appointed a citizens' committee to assist the state with the work involved in listing the district.The residential areas within the district achieved their maturity before 1900, though Sycamore has grown considerably from the 3,330 or so that lived there from about 1900 until the 1970s most of the historic district remains intact as it was organized in 1978.